The possibility of a priori determination of the reliability of the functioning of complex program complexes

Mathematical models with expert determination of their parameters in a particular project allow to predict the reliability of program complexes at the stages of autonomous and complex debugging. While reliability is low in these conditions, errors are detected quite often. For a priori determination and prediction of NPS, at the stages of testing and putting into operation, repeated attempts were made to analytically calculate the probability of errors and failures in operation. Attempts were unsuccessful due to their low reliability. In complex software packages there is no base for an a priori analytical calculation of reliability indicators, there are no exact indicators of the average failure rate of elements (operations, functions, modules). A method of a priori calculation of the reliability of complex PS has been developed, but it is not constructive, because based on probabilistic estimates of the occurrence of a failure depending on the stage of PS development.
The unpredictability of specific errors in programs and data leads to the expediency of consistent methodical analysis of the possibility of the appearance of any type of errors and the need to eliminate them at the earliest stages of debugging.
The study of the characteristics of the manifestation and elimination of errors during debugging, testing and operating programs is the basis for a generalized experimental prediction of the potential reliability of their functioning and safety of use.